//数据
// horsepower马力,dollar_ value 价格,
// in_stock 库存

const cars = [
    {
        name: "Ferrari FF",
        horsepower: 660,
        dollar_value: 700000,
        in_stock: true
    },
    {
        name: "Spyker C12 Zagato",
        horsepower: 650,
        dollar_value: 648000,
        in_stock: false
    },
    {
        name: "Jaguar XKR-S",
        horsepower: 550,
        dollar_value: 132000,
        in_stock: false
    },
    {
        name: "Audi R8",
        horsepower: 525,
        dollar_value: 114200,
        in_stock: false
    },
    {
        name: "Aston Martin One-77",
        horsepower: 750,
        dollar_value: 1850000,
        in_stock: true
    },
    {
        name: "Pagani Huayra",
        horsepower: 700,
        dollar_value: 1300000,
        in_stock: false
    }
]
const fp = require('lodash/fp')

//练习1
const getData = (res) => {
    return (data) => data[res]
};
const isLastInStock = fp.flowRight(getData('in_stock'), fp.first, fp.reverse)
console.log(isLastInStock(cars))

//练习2
const getFirstDataName = fp.flowRight(fp.prop('name'), fp.first)
console.log(getFirstDataName(cars))

//练习3
let _average = function (xs) {
    return fp.reduce(fp.add, 0, xs) / xs.length
}
// let averageDollarValue = function (cars) {
//     let v = fp.map(function (car) {
//         return car.dollar_value
//     },cars)
//     return _average(v)
// }
let averageDollarValue = fp.flowRight(_average, fp.map(fp.prop('dollar_value')))
console.log(averageDollarValue(cars))

//练习4
const _toLower = function (str) {
    return fp.toLower(str)
}
let _underscore = fp.replace(/\W+/g, '_')
const sanitizeName = fp.flowRight(fp.map(_toLower), fp.map(_underscore))
console.log(sanitizeName(['Hello World']))
